.gradient-bg {
	display: flex;
	justify-content: center;
	align-items: center;
	height: 100%;
	background: linear-gradient(135deg, red, orange, green, blue, purple) left center/400% 400%;
	font-weight: bold;
	font-size: 100px;
	color: #fff;
	animation: move 10s infinite;
}
@keyframes move {
	0%,
	100% {
		background-position-x: left;
	}
	50% {
		background-position-x: right;
	}
}